My fiance and I are hoping to rent a house in the near future, it will be the first time either of us has rented a place - and we know very little!

We've had a look round the websites of local estate agents, taken an interest in a few properties but there are so many abbreviations and numbers in what to us looks like random places. We've managed to figure most of them out by researching ourselves, but other things we are still confused about - can one of you experts take a look and let us know what the 18 in brackets at the end means please? :D